Never mind the Apple Watch: Where's Apple Glass?

Wearables. We hear a lot about wearables, and Apple's staged to make a big entrance in 2015 with the release of the Apple Watch. In the interim, other companies are making plays in another segment of the wearables market: glasses. Google may have gone to ground for a bit to rework its Glass product, but Microsoft is charging full speed ahead with HoloLens and Facebook last year acquired Oculus VR, makers of the Rift headset. Where's Apple in all this?